Generic strategies and performance: evidence from manufacturing firms

Purpose – The purpose of this study is to examine the relationship between business-level strategy and organisational performance and to test the applicability of Porter's generic strategies in explaining differences in the performance of organisations. Design/methodology/approach – The study was focussed on manufacturing firms in the UK belonging to the electrical and mechanical engineering sectors. Data were collected through a postal survey using the survey instrument from 124 organisations and the respondents were all at CEO level. Both objective and subjective measures were used to assess performance. Non-response bias was assessed statistically and it was not found to be a major problem affecting this study. Appropriate measures were taken to ensure that common method variance (CMV) does not affect the results of this study. Statistical tests indicated that CMV problem does not affect the results of this study. Findings – The results of this study indicate that firms adopting one of the strategies, namely cost-leadership or differentiation, perform better than “stuck-in-the-middle” firms which do not have a dominant strategic orientation. The integrated strategy group has lower performance compared with cost-leaders and differentiators in terms of financial performance measures. This provides support for Porter's view that combination strategies are unlikely to be effective in organisations. However, the cost-leadership and differentiation strategies were not strongly correlated with the financial performance measures indicating the limitations of Porter's generic strategies in explaining performance heterogeneity in organisations. Originality/value – This study makes an important contribution to the literature by identifying some of the gaps in the literature through a systematic literature review and addressing those gaps.

“There’s something very familiar about all this”: generic play and performance in the Back to the Future trilogy (Robert Zemeckis, 1985, 1989, 1990)

The Back to the Future Trilogy incorporates several different generic elements, including aspects of the fifties teen movie, science fiction, comedy and the western. These different modes playfully intertwine with each other creating a complex world of repetitions, echoes and modulations. This essay seeks to interrogate the construction of generic elements and the play between them through a close analysis of a repeated performance. Genre is signalled through various strategies employed within the construction of mise-en-scène, a significant portion of this, as I would like to argue, is transmitted through performance. The material detail of a performance – incorporating gesture, movement, voice, and even surrounding elements such as costume – as well as the way it its presented within a film is key to the establishment, invocation and coherence of genre. Furthermore, attention to the complexity of performance details, particularly in the manner in which they reverberate across texts, demonstrates the intricacy of genre and its inherent mutability. The Back to the Future trilogy represents a specific interest in the flexibility of genre. Within each film, and especially across all three, aspects of various genres are interlaced through both visual and narrative detail, thus constructing a dense layer of references both within and without the texts. To explore this patterning in more detail I will interrogate the contribution of performance to generic play through close analysis of Thomas F. Wilson’s performance of Biff/Griff/Burford Tannen and his central encounter with Marty McFly (Michael J. Fox) in each film. These moments take place in a fifties diner, a 1980s retro diner and a saloon respectively, each space contributing the similarities and differences in each repetition. Close attention to Wilson’s performance of each related character, which contains both modulations and repetitions used specifically to place each film’s central generic theme, demonstrates how embedded the play between genres and their flexibility is within the trilogy.

Enrichment and stability: a phenomenological coupling of energy value and carrying capacity

Simple predator–prey models with a prey-dependent functional response predict that enrichment (increased carrying capacity) destabilizes community dynamics: this is the ‘paradox of enrichment’. However, the energy value of prey is very important in this context. The intraspecific chemical composition of prey species determines its energy value as a food for the potential predator. Theoretical and experimental studies establish that variable chemical composition of prey affects the predator–prey dynamics. Recently, experimental and theoretical approaches have been made to incorporate explicitly the stoichiometric heterogeneity of simple predator–prey systems. Following the results of the previous experimental and theoretical advances, in this article we propose a simple phenomenological formulation of the variation of energy value at increased level of carrying capacity. Results of our study demonstrate that coupling the parameters representing the phenomenological energy value and carrying capacity in a realistic way, may avoid destabilization of community dynamics following enrichment. Additionally, under such coupling the producer–grazer system persists for only an intermediate zone of production—a result consistent with recent studies. We suggest that, while addressing the issue of enrichment in a general predator–prey model, the phenomenological relationship that we propose here might be applicable to avoid Rosenzweig’s paradox.

Enrichment and ecosystem stability: effect of toxic food

Enrichment in resource availability theoretically destabilizes predator–prey dynamics (the paradox of enrichment). However, a minor change in the resource stoichiometry may make a prey toxic for the predator, and the presence of toxic prey affects the dynamics significantly. Here, theoretically we explore how, at increased carrying capacity, a toxic prey affects the oscillation or destabilization of predator–prey dynamics, and how its presence influences the growth of the predator as well as that of a palatable prey. Mathematical analysis determines the bounds on the food toxicity that allow the coexistence of a predator along with a palatable and a toxic prey. The overall results demonstrate that toxic food counteracts oscillation (destabilization) arising from enrichment of resource availability. Moreover, our results show that, at increased resource availability, toxic food that acts as a source of extra mortality may increase the abundance of the predator as well as that of the palatable prey.

The stability of ecosystems: a brief overview of the paradox of enrichment

In theory, enrichment of resource in a predator-prey model leads to destabilization of the system, thereby collapsing the trophic interaction, a phenomenon referred to as "the paradox of enrichment". After it was first proposed by Rosenzweig (1971), a number of subsequent studies were carried out on this dilemma over many decades. In this article, we review these theoretical and experimental works and give a brief overview of the proposed solutions to the paradox. The mechanisms that have been discussed are modifications of simple predator-prey models in the presence of prey that is inedible, invulnerable, unpalatable and toxic. Another class of mechanisms includes an incorporation of a ratio-dependent functional form, inducible defence of prey and density-dependent mortality of the predator. Moreover, we find a third set of explanations based on complex population dynamics including chaos in space and time. We conclude that, although any one of the various mechanisms proposed so far might potentially prevent destabilization of the predator-prey dynamics following enrichment, in nature different mechanisms may combine to cause stability, even when a system is enriched. The exact mechanisms, which may differ among systems, need to be disentangled through extensive field studies and laboratory experiments coupled with realistic theoretical models.

Postprandial enrichment of triacylglycerol-rich lipoproteins with omega-3 fatty acids: lack of an interaction with apolipoprotein E genotype?

Background: We have previously demonstrated that carrying the apolipoprotein (apo) E epsilon 4 (E4+) genotype disrupts omega-3 fatty acids (n − 3 PUFA) metabolism. Here we hypothesise that the postprandial clearance of n − 3 PUFA from the circulation is faster in E4+ compared to non-carriers (E4−). The objective of the study was to investigate the fasted and postprandial fatty acid (FA) profile of triacylglycerol-rich lipoprotein (TRL) fractions: Sf >400 (predominately chylomicron CM), Sf 60 − 400 (VLDL1), and Sf 20 − 60 (VLDL2) according to APOE genotype. Methods: Postprandial TRL fractions were obtained in 11 E4+ (ε3/ε4) and 12 E4− (ε3/ε3) male from the SATgenε study following high saturated fat diet + 3.45 g/d of docosahexaenoic acid (DHA) for 8-wk. Blood samples were taken at fasting and 5-h after consuming a test-meal representative of the dietary intervention. FA were characterized by gas chromatography. Results: At fasting, there was a 2-fold higher ratio of eicosapentaenoic acid (EPA) to arachidonic acid (P = 0.046) as well as a trend towards higher relative% of EPA (P=0.063) in theSf >400 fraction of E4+. Total n − 3 PUFA in the Sf 60 − 400 and Sf 20 − 60 fractions were not APOE genotype dependant. At 5 h, there was a trend towards a time × genotype interaction (P=0.081) for EPA in theSf >400 fraction. When sub-groups were form based on the level of EPA at baseline within the Sf >400 fraction, postprandial EPA (%) was significantly reduced only in the high-EPA group. EPA at baseline significantly predicted the postprandial response in EPA only in E4+ subjects (R2 = 0.816). Conclusion: Despite the DHA supplement contain very low levels of EPA, E4+ subjects with high EPA at fasting potentially have disrupted postprandial n − 3 PUFA metabolism after receiving a high-dose of DHA. Trial registration: Registered at clinicaltrials.gov/show/NCT01544855.

Reinterpreting ‘generic structure’: evolution, application and limitations of a concept

This paper traces the evolution of thegeneric structure concept in system dynamics and discusses the different practical uses to which they have been put. A review of previous work leads to the identification of three different views of what a ‘generic structure’ is and, hence, what transferability means. These different views are distinguishable in application as well as in theory. Examination of these interpretations shows that the assumptions behind them are quite distinct. From this analysis it is argued that it is no longer useful to treat ‘generic structure’ as a single concept since the unity it implies is only superficial. The conclusion is that the concept needs unbundling so that different assumptions about transferability of structure can be made explicit, and the role of generic structures as generalisable theories of dynamic behaviour in system dynamics theory and practice can be debated and clarified more effectively.

Can we have confidence in generic structures?

The system dynamics concept of `generic structure' is dividable into three sub-types. This paper analyses the validity of these three, using both practical and theoretical perspectives. Firstly, a new set of measures is developed for generating validity-`confidence'-amongst a group using generic structures in a practical modelling situation. It is concluded that different confidence criteria are implicitly employed; there is an argument for trading-off model precision and analytical quality for simplicity and ease of use and future research is needed to combine these `process' and `content' aspects of confidence. From a theoretical stance it is shown that with two of the sub-types a scientific notion of confidence is achievable whereas the third (`archetypes') involves merely metaphorical thinking. It is concluded that the theoretical status of archetypes requires further development, whilst ensuring that its benefits are retained.

Reinterpreting 'generic structure': evolution, application and limitations of a concept

This paper traces the evolution of the generic structure concept in system dynamics and discusses the different practical uses to which they have been put. A review of previous work leads to the identification of three different views of what a generic structure is and, hence, what transferability means. These different views are distinguishable in application as well as in theory. Examination of these interpretations shows that the assumptions behind them are quite distinct. From this analysis it is argued that it is no longer useful to treat generic structure as a single concept since the unity it implies is only superficial. The conclusion is that the concept needs unbundling so that different assumptions about transferability of structure can be made explicit, and the role of generic structures as generalisable theories of dynamic behaviour in system dynamics theory and practice can be debated and clarified more effectively.

Label-free enrichment of avian Leucocytozoon using flow cytometric sorting

The group of haemosporidian parasites is of general interest to basic and applied science, since several species infect mammals, leading to malaria and associated disease symptoms. Although the great majority of haemosporidian parasites appear in bird hosts, as in the case of Leucocytozoon buteonis, there is little genomic information about genetic aspects of their co-evolution with hosts. Consequently, there is a high need for parasite-enrichment strategies enabling further analyses of the genomes, namely without exposure to DNA-intercalating dyes. Here, we used flow cytometry without an additional labelling step to enrich L. buteonis from infected buzzard blood. A specific, defined area of two-dimensional scattergramms was sorted and the fraction was further analysed. The successful enrichment of L. buteonis in the sorted fraction was demonstrated by Giemsa-staining and qPCR revealing a clear increase of parasite-specific genes, while host-specific genes were significantly decreased. This is the first report describing a labelling-free enrichment approach of L. buteonis from infected buzzard blood. The enrichment of parasites presented here is free of nucleic acid-intercalating dyes which may interfere with fluorescence-based methods or subsequent sequencing approaches.

A parallel formulation for the simulation of a generic branch predictor

A parallel formulation for the simulation of a branch prediction algorithm is presented. This parallel formulation identifies independent tasks in the algorithm which can be executed concurrently. The parallel implementation is based on the multithreading model and two parallel programming platforms: pthreads and Cilk++. Improvement in execution performance by up to 7 times is observed for a generic 2-bit predictor in a 12-core multiprocessor system.